1. Field of the Invention
This invention relates to an ink jet type recording apparatus such as a printer which forms ink images on a medium such as recording paper by melting an ink that is solid at ambient temperature (hot-melt ink) and jetting the molten, and thus liquid droplets of ink. More particularly, it is directed to an ink jet printer head for use in the ink jet type recording apparatus.
2. Prior Art
A conventional ink jet type recording apparatus using hot-melt ink has the advantage of being compatible with many kinds of recording paper, of not causing the ink to evaporate while the apparatus is not being used, and of causing no clogging of its ink jetting nozzles. An ink jet head used in this apparatus has been constituted by a nozzle-formed member having a plurality of nozzle orifices, a heater, a piezoelectric converter, and an ink reservoir, and the nozzle-formed member has been unitized with the head forming members including the piezoelectric converter (U.S. Pat No. 4,631,557, Japanese Utility Model Application (UPA) No. 41652/1981 (the term "UPA" as used herein means "Unexamined Published Application").
The above-described conventional ink jet head has a structure in which its components having different thermal expansion coefficients are subjected to thermal stresses due to temperature variations that result from the melting of the ink. Deformations of the components caused by the thermal stress impose problems in terms of ensuring proper accuracy for stable performance and achieving undamageable structures for high reliability.